Type:
Module
The Comparable mixin is used by classes whose objects may be
ordered. The class must define the <=> operator, which
compares the receiver against another object, returning -1, 0, or +1
depending on whether the receiver is less than, equal to, or greater than
the other object. If the other object is not comparable then the
<=> operator should return nil. Comparable
uses <=> to implement the conventional comparison
operators (<, <=, ==,
>=, and >) and the method
between?.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | class SizeMatters include Comparable attr :str def <=>(anOther) str.size <=> anOther.str.size end def initialize(str) @str = str end def inspect @str endends1 = SizeMatters.new("Z")s2 = SizeMatters.new("YY")s3 = SizeMatters.new("XXX")s4 = SizeMatters.new("WWWW")s5 = SizeMatters.new("VVVVV")s1 < s2 #=> trues4.between?(s1, s3) #=> falses4.between?(s3, s5) #=> true[ s3, s2, s5, s4, s1 ].sort #=> [Z, YY, XXX, WWWW, VVVVV] |